18. OMG! Did you make that?

19. No - they're actual old horror movies

and apparently were part of a double feature. It: The Terror From Beyond Space is about a blood-sucking creature from Mars that stows away on a space craft that visits the red planet and starts killing the crew one-by-one on the return trip to Earth. It's been shown a few times on TCM. It's one of the better oldie horror movies and was the direct inspiration for the film Alien.